Member Avatar for THEN00B

I have an HP Pavilion 740n with a pentium 4 1.6ghz cpu, 2 x 256mb RAM (max RAM is 2gig) and onboard graphics.

My problem is I wanted to upgrade the video card and RAM so I bought a card and a 512mb stick. I took out the 2 256mb sticks and added 2 512mb before putting the fx card in. Now when I power on the comp it starts but makes a loud beep for a few seconds, stops then does it again, no picture on the monitor either.

I tried putting the 256mb sticks in and the same thing happens. Also there was an AGP card in the machine but not installed. Before sticking that in there I was having the same problems with the loud beep but could eventually get to the BIOS. Having the video card seemed to help even though it wasn't installed, comp always started correctly and never crashed.

I even tried all possible combinations including the new card and taking both out. Now when I power on the comp it starts but makes a loud beep for a few seconds, stops then does it again, no picture on the monitor either.

I hope someone can help, if you need more specs I will have to look them up because I forgot. Thanks in advance.

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Good start from — here is a compact, prioritized troubleshooting checklist to isolate why a system powers up but fails POST and emits BIOS beeps. It expands on the earlier suggestions and focuses on tests that narrow the fault quickly.

First, record the exact beep pattern (length of beeps, number, and pauses). Lookup the BIOS beep-code table for the board (AMI/Award/Phoenix differ). A reliable quick reference is Computer Hope’s beep-code summary. The pattern will point toward memory, video, or motherboard/CPU problems and saves time.

Bench-test method (do this before swapping parts): unplug mains and ground yourself. Remove all nonessential cards/drives and leave only the CPU, one stick of RAM, speaker, keyboard and monitor connected. Try a single DIMM in each slot, one stick at a time, and repeat with any spare known-good RAM. If a single stick in a particular slot posts, the trouble is either that DIMM or that slot. This expands on ’s isolation idea and addresses ’s note about defective parts.

If the single-DIMM bench fails, check the PSU next. Fans spinning isn’t proof of good rails — either swap in a known-good PSU or measure 12V/5V rails under light load (do not open the PSU). Inspect the motherboard for bulging/leaking capacitors, scorch marks, or bent CPU pins and reseat the CPU/heatsink carefully. ’s CPU suggestion is valid but usually a later step — CPU faults are less common than memory, PSU, or board faults.

If none of the above narrows it down, the most likely culprits are the motherboard or PSU. When asking for more help later, include the beep pattern as plain text, BIOS vendor (if visible on splash or board), photos of the board (caps, slots, connectors), and which bench steps were tried. Always unplug power and discharge capacitors before touching components.

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Member Avatar for willcomp

Unplug PC. Remove video card(s). Install original memory. Clear CMOS. Plug back in and try to boot. Describe what happens then.

Member Avatar for forumdude123

one of the items may be defective, or unsupported by your pc.

Member Avatar for jah666

one of the items may be defective, or unsupported by your pc.

I think most probably your processor is defective> Just last week I had a problem like that with my PC it powers up but never boots and has this long beeping sound so I'd suggest you try looking at the processor.

Member Avatar for THEN00B

Sorry about the late response but I had no computer. I ended up buying a refurbished comp while I look more into the problems of the other one.

First I did do what Willcomp suggested and ended up with the same results even in multiple configs. When I have time I will look into the cpu on the old beast, I have another cpu I know works so I will just slap that on and see what happens.

Thanks everyone

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